Development of selective stripping method by DTPA for trivalent actinides from rare earth elements in DIDPA solvent; Evaluation of separation performance by simulation code

Fujiwara, Takeshi; Morita, Yasuji  

In the 4-Group Partitioning Process developed in Japan Atomic Energy Research Institute (presently: Japan Atomic Energy Agency), we examined selective stripping method by DTPA for Am and Cm from the rare earth elements (REs) in DIDPA solvent. In the present study, the performance of the selective stripping and the optimization of the separation process was examined by a simulation program which uses the values of distribution ratios of Am and REs obtained by batch experiments. The validity of the simulation program was confirmed by comparing the results of the simulation with the results of continuous stripping tests of REs with DTPA solution from the DIDPA solvent using mini-mixer-settlers. The distributions of the REs in mini-mixer-settlers were adequately predictable in the condition with low concentration of the REs by the simulation program. It is effective to add the scrubbing steps by organic solvent in order to decrease the amount of REs that contaminate the Am and Cm product.